Fuel compositions



Jan. 9, 1968 s, BELAK T 3,3625800 FUEL COMPOSITIONS Filed Sept. 21. 1966 WAX OR POLYPROPYLENE TOP I F'z/gzl BITUMINOUS MATERIAL PARTICULATE POLYSTYRENE OR RIGID POLYURETHANE CARDBOARD CONTAINER J I Z NAPHTHALENE IGNITOR ALUMINUM FOIL I CARDBOARD CONTAINER SIDES BITUMINOUS MATERIAL PARTICULATE 4 MATERIAL METAL END BITUMINOUS MATERIAL NAPHTHALENE INVENTORS WESLEY R. CHERRY ANDREW J. BOZZELLI STEVEN G. BELAK ROBERT H. CAMPBELL United States Patent 3,362,800 FUEL COMPOSITIONS Steven G. Belak, Claymont, Del., and Robert H. Campbell, Brookhaven, Wesley R. Cherry, Prospect Park, and Andrew J. Bozzelli, Springfield, Pa., assignors to Sun Oil Company, Philadelphia, Pa., a corporation of New Jersey Filed Sept. 21, 1966, Ser. No. 581,087 8 Claims. (Cl. 44-6) The present invention relates to a novel fuel composition and more particularly to solid fuel compositions made from bituminous material.

The fuel of this invention is best utilized as a smudge pot fuel. Smudge pots are used for the protection of crops from frost damage. The pots are placed at spaced intervals throughout the groves or fields to be protected and when the crop is threatened by frost, the fuel in the pots is ignited. The heat given oif by the burning fuel is sufficient to prevent frost damage.

Asphalt is defined by the American Society for Testing Materials as a dark brown to black cementitious material, solid or semisolid in consistency, in which the predominating constituents are bitumens which occur in nature as such or are obtained as residue in refining petroleum. In addition, asphalts characteristically contain a bitumen fraction insoluble in parafiin naphtha. This fraction is called the asphaltenes. The solid or semisolid residues from refining operations are usually called cracked asphalt, petroleum pitch, thermal pitch or cracking-coil pitch.

Petroleum asphalts are derived principally from four types of processes. They are straight run asphalts, obtained by atmospheric, steam, or vacuum distillation of lower boiling components of the oil; asphalts produced as the bottoms product from a combined distillation process; asphalts separated by solvent extraction, e.g., the propane deasphalting process, and chemically treated asphalts, such as air blown, oxidized, sulfurized, and chlorinated asphalts.

The term bitumens is a more generic term than asphalt and, according to the American Society for Testing Materials, relates to Mixtures of hydrocarbons of natural or pyrogenous origin; or combinations of both, frequently accompanied by their non-metallic derivatives, which may be gaseous, liquid, semisolid, or solid, and which are completely soluble in carbon disulfide. In usual commercial practice the term bitumens is restricted to the semisolid or solid bitumens which include asphalts and tars and pitches. The latter two are derived from stocks obtained by destructive heat action on crude oil fractions, coals or other organic raw materials. In this specification, the term bitumens or the like will be restricted to this latter definition.

Bituminous materials, particularly asphalts, alone Will not burn or Will give poor combustion when ignited at ambient temperatures. It has surprisingly been found that asphalt containing a minor amount of particulate polystyrene or rigid polyurethane when ignited will burn almost completely with little ash. These fuel compositions are prepared by simply heating the asphalt until it be comes flowable and adding, with agitation, the polymeric material in the form of small particles. The resulting composition, when cooled, is solid and is readily ignitable. When ignited, the composition burns slowly, giving off significant amounts of heat for a sufficient period of time to make it quite suitable as a fuel for the prevention of frost in orchards.

Either polystyrene or rigid polyurethane foams are suitable for adding to asphalt to prepare the compositions of this invention. A rigid urethane foam may be defined as 3,362,800 Patented Jan. 9, 1968 a stiff cellular urethane plastic which becomes permanently deformed when compressed beyond its yield point. Differences in rigidity are indicated by the description of forms as rigid or semirigid. In this specification the term rigid polyurethane excludes flexible but includes semirigid foams.

A variety of organic polyisocyanates can be employed in producing the urethane foams used in this invention, although aromatic di-isocyanates are generally used. The di-isocyanates include 2,4- and 2,6-toluene di-isocyanates and mixtures thereof; 1,4- and LS-naphthalene di-isocyanates; phenyl di-isocyanates such as 4,4-di-phenylmethane, p-dixylyl-methane-4,4'-di-isocyanate; and tri-isocyanates such as diphenyl-4,6,4'-tri-isocyanate. Side chain di-isocyanates like naphthylylene and xylylene di-isocyanates can also be used.

The isocyanates react with any compound containing an active hydrogen (i.e., one connected to an atom more electro-negative than carbon). Polyols having a molecular weight ranging from about 500 to about 10,000 are commonly used as the source of active hydrogen. These include polyesters and polyethers. The polyesters are derived from polyfunctional acids and polyols such as the adipates, succinates, sebacates, azelates and phthalates of pentaerythritol, xylitol and sorbitol. Suitable polyethers include the condensation products of propylene oxide with polyfunctional alcohols and amines such as glycerol, pentaerythritol, xylitol, sorbitol, a-methyl glucoside, and ethylenediamine.

The urethane foam may be prepared by batch, semicontinuous or continuous methods using bench equipment, or commercial foam machines. These preparations are well known in the art, as for example, see Rigid Urethane Foams-II Chemistry and Formulation by C. M. Barringer, Polymer Chemicals Department, E. I. du Pont de Nemours and Company, Wilmington, Del.

There are three forms of cellular polystyrenes all of which may be used in preparing the composition of these inventions; extruded preformed foam in the shape of logs, planks or boards, expandable polystyrene in the form of free flowing beads containing an integral blowing agent, and self-expanding systems which are combinations of expandable polystyrene beads and a thermosetting plastic. These three types have quite similar properties.

Polymerization of styrene proceeds readily, using all methods of polymerization, under the influence of heat and/or an initiator. Usually such processes as the emulsion process, suspension process or the mass process, all of which are well known are used. The commercial polystyrene produced by these processes is a clear, transparent thermoplastic material capable of transmitting slightly more than percent of white light.

Polystyrene soften slightly above C. and becomes a viscous fluid at temperatures around C. It has a heat distortion temperature of 75 to 85, a twenty-fourhour Water adsorption of about 0.04 percent, and a tensile strength of 6-,000 to 8,500 p.s.i. Its density of 1.05 makes it one of the lightest plastics.

Polystyrene, suitable for use in the composition of this invention, may be made by any of the procedures well known in the art. For example, see Polymers and Resins, Broge Golding, D. Van Nostand Company, Inc., New York, 1959.

Mixtures of polymer and bitumen materials are known. For example, US. Patent No. 2,888,407 teaches a closed cell expanded material formed by mixing bitumen, a blowing agent and monomeric styrene, and heating the mixture so that the styrene is converted into a hard blown polymer.

On the other hand, the compositions of this invention are produced by forming the expanded or expandable polymer additive free from the bituminous materials by one of the numerous methods known in the art as for example, US. Patent No. 2,986,537. The polymer obtained is then divided into pieces ranging up to about two inches in diameter or larger. Hereinafter in this specification particulate polystyrene or polyurethane will refer to polystyrene and polyurethane produced by one of the processes referred to above and reduced into particles ranging up to about two inches in diameter or larger. After the polymeric material has been particularized, it is mixed with the bituminous material. The bituminous material may be heated to facilitate mixing. The resulting composition differs from that of US. Patent No. 2,888,- 407 and from the art in general. Surprisingly the bituminous material-particulate foam polymer mixtures of this invention provide an excellent fuel for burning for the prevention of frost in fruit orchards.

The compositions of this invention comprise bituminous material containing a minor amount of a particulated polymer selected from the group consisting of particulate polystyrene and particulate rigid polyurethane. Preferably the composition contains 0.05 to weight percent of the polymer based on the weight of the total composition. The particulate expanded polystyrene or polyurethane comprises pieces ranging up to 2 inches in diameter, preferably, to /2 inch in diameter, but particle size is not critical so long as the plastic material is at least somewhat particularized for dispersing throughout the bituminous material to form a mixture with a continuous bitumen phase and dispersed polymer particles.

The compositions may be prepared by heating the bituminous material to a temperature at which it will flow but below a temperature which would destroy the plastic. Usually this temperature is in the range of 85 to 175 F. The bituminous material is added to the divided polymer and the mixture is stirred. The mixture is then cooled to give a solid fuel quite suitable for use as a smudge pot fuel.

The fuel composition may be placed in a paper or fiber board container, a metal can, or plastic bag and used as such or a combustion aid, such as a solvent spirit, may be added in weight percent of the total composition of up to about 10 percent. A particularly useful composition for use as a smudge pot fuel comprises asphalt, solvent spirits and the particulate polystyrene. This fuel can -be ignited and burned at F.

The following table gives characteristics of some typical petroleum solvent spirits which may be used in the composition of this invention.

TABLE I Specific Gravity at 60 F 0. 864 0. 760 0. 704 Distillation:

Initial Boiling Point ("O 185 110 10% distilling to (3.). 193 117 62 distilling to (3.)- 196 123 distilling to C.) 201 137 Final Boiling Point O.) 210 160 Flash-point (closed) F.) 154 below 73 below 73 Aromatics (percent by weight) 60 12 7 Ksuri butanol number 56 3 32 Dilution ratio (butyl acetate). 1:65 1:25 1:22

Naphthalene in any form may be added to the fuel compositions as an ignition aid. It may be added as a powder, sprinkled on the top of the fuel composition, or preferably wrapped in a plastic bag and merely set on top of the fuel. The naphthalene is not particularly necessary with the polymer to make a suitable fuel for use in preventing frost but is desirable to aid ignition of the fuel when ignited with a gasoline torch. The naphthalene may be mixed with wax in from 0.5 to 30 Weight percent naphthalene per weight of naphthalene and wax and this composition may be used as an ignition aid to the polymer containing fuels or it may be used as a suitable heat producing fuel by itself. When used as an ignition aid without wax, the naphthalene may be present in a minor amount compared to the asphalt but preferably the naphthalene is present in up to 10 weight percent based on the total fuel composition weight.

These fuel compositions containing naphthalene are particularly interesting since the naphthalene may be used alone in asphalt or in conjunction with the particularized polymers as an ignition aid and when either used alone or with the polymer, the naphthalene is effective in very small proportions and in any form. For example, asphalt containing only a pinch of powdered naphthalene, burns completely to give little ash even though the asphalt alone would burn unsatisfactorily or not at all.

The asphalt-polymer fuel in its container may be fitted with a suitable top such as a wax layer, a wax-rosin or asphalt-rosin mixture, a polyethylene disc or an asphaltpolystyrene or asphalt-polyurethane top which has been formed by foaming polystyrene beads or polyurethane in place with the asphalt. These latter two tops are particularly suitable since they Serve as an igniter for the fuel as Well as a seal to prevent cold flow. The wax-rosin tops prevent cold flow, strengthen the fuel containers to allow stacking and also serve as an igniter for the fuels.

The drawing illustrates some of the compositions within the comprehension of this invention. FIGURE 1 shows a bituminous fuel composition containing particulate polystyrene or rigid polyurethane in a container with a Wax or polypropylene top; FIGURE 2 shows the same fuel contained in a small one-gallon oil can with an aluminum foil outside lining, a metal end and a plastic lid fitted with a naphthalene igniter; FIGURE 3 shows a container holding a naphthalene-asphalt fuel composition.

The following examples illustrate the invention:

Examples I and II The solid fuel units, of compositions and quantities indicated in columns 1 and 2 of Table II, were prepared by the following procedure:

The bottom of each container was fastened to the container sidewall and the container filled approximately half full with particles of polystyrene foam in medium size ranging from to /2 inch in diameter. A mixture of asphalt and petroleum spirits, as indicated in Table II, was heated to about 170 F. and stirred into the foam to fill the container to approximately one inch from the top. Stirring was continued for approximately 5 to 10 seconds. Asphalt of characteristics indicated in column 2 of Table III was then heated to to F. and added to the top of the foam-asphalt mixture to a depth of approximately one-quarter inch. The composition was then cooled and covered with a polyethylene disc cover. In run 2, 0.5 pounds of naphthalene were sprinkled onto the top of the solidified fuel.

TABLE IL-COMPOSITION NUMBER Totai Pounds/Container 30. O 30. 0 29. 5 29. 5 29.5 30. 0 Pounds Asphalt A 26. 0 26.0 27. 5 27.5 Pounds Solvent Spirits. l. 4 1. 4 1. 5 1. 5 Pounds Asphalt B 2. 0 2.0 29. 0 0. 5 Pounds Polystryene. O. 6 0.1 0.5 0. 5 0.5 0. 5 Pounds Asphalt C 29. 0 Pounds Naphthalene 0. 5 Container Deseriptioin Bug- Container Cover Number 01 Units Produced. 1, 200 N l Cylindrical shape; metal bottom; kraft board walls; aluminum foil laminated to sides.

2 Cardboard container with fire proof paint with wire screening inside container.

* Polyethylene disc, 24" diameter.

4 Wax covered lid.

5 Tied with string.

TABLE III Asphalt A B C Conradson Carbon, percent 15 8. 5 11.0 Flash Point (C 1 F.) 600 540 230 Fire Point (COC 1 F.)" 700 620 Melt Point, F 128 Viscosity at 210 F. (SFS 2, 000 125 Viscosity at 122 F. (SFS 122 Density (lbs/gal.) 7. 7. 5 Sulfur Percent 1. 2 0.75 2. 5

1 COO-Cleveland Open Cup D92.

2 SFS-Sabolt Furol Seconds.

Examples III to VI The fuel compositions numbers 3, 4, 5, and 6, of Table II were produced by mixing the bituminous material with polystyrene in the same manner that the fuels of Exampics I and II were prepared. The compositions numbers 3, 4, and 5 Were particularly interesting in that the screening material on the inside of the container prevented ash from the burning container from curling back onto the fuel. In some packages this ash smothered out the burning fuel.

Examples VII and VIII A one-pint cardboard ice cream container was filled with an asphalt with the properties of an asphalt A of Table III. This fuel composition would not ignite. A second composition was prepared by adding 1 percent by Weight of expanded polystyrene beads ranging in size from /2 to inch in diameter. This second composition burned readily when ignited with a gasoline torch and did not go out until all the asphalt had been consumed.

These two examples illustrate the unusual properties of the composition of this invention and the unexpected properties imparted to asphalt compositions by the addition of polystyrene.

Examples IX and X Two fuel compositions were prepared according to the procedure of Example I except that one fuel contained particulate flexible polyurethane foam instead of polystyrene and the second fuel contained rigid polyurethane foam. The first fuel, when ignited, burned slightly, then smothered itself out. The second fuel burned well, giving results similar to those achieved with the polystyrene added fuels.

In using the fuel compositions of this invention for the prevention of frost in fruit orchards the bituminous fuels containing the foam polymer may be placed in a container such as, for example, a metal can, a kraft paper carton or in a plastic bag which can then be buried in the ground at such a depth as to allow the top opening to be ignited.

Examples XI and X11 A commercial package of fuel was prepared as follows: A cylindrically wound cardboard carton, 13 inches high and 10.5 inches in diameter was filled With an asphalt having the properties of asphalt C of Table III mixed with one-half pound of flaked napthalene. The entire package was coated with bituminous material. A molded polyethylene lid was fitted over the top of the composition and secured with a weather resistant pressure sensitive tape to give a complete package weighing 30 pounds.

The same fuel was added to a one-gallon cardboard oil can with aluminum foil covered sides and a metal end. A polyethylene lid was fitted over the top of the can and secured with a pressure sensitive tape to give an 8 pound fuel package.

What is claimed is:

1. A solid fuel composition comprising a major portion of bituminous material and a minor portion of a particulate material selected from the group consisting of particulate polystyrene and particulate rigid polyurethane, said particulate material mixed with said bituminous material as dispersed particles in a continuous bituminuous phase.

2. A solid fuel composition of claim 1 in which the particulate material ranges from about A to about /2 inch in diameter.

3. A solid fuel composition according to claim 1 additionally comprising up to 10 weight percent based on the weight of the total composition of a petroleum solvent spirit.

4. A solid fuel composition according to claim 1 in which the particulate material is particulate rigid polyurethane. Y

5. A solid fuel composition comprising a major portion of bituminous material and a minor portion of naphthalene.

6. A solid fuel composition according to claim 5 addi tionally comprising up to 10 weight percent based on the weight of the total composition of a petroleum solvent spirit. 3

7. A solid fuel composition according to claim 5 additionally comprising a minor portion of a particulate material selected from the group consisting of particulate polystyrene and particulate rigid polyurethane, said particulate material mixed with said bituminous material as dispersed particles in a continuous bituminous phase.

8. A solid fuel composition according to claim 7 in which the particulate material ranges from about A to about /2 inch in diameter.

References Cited UNITED STATES PATENTS 703 2/1873 Clark 447.5 1,916,573 7/1933 Jessen 4438 2,276,220 3/1942 Le Veillo l2659.5 2,531,828 11/1950 Schultz 44-41 2,599,986 6/1952 Goebel et al 26028.5 2,662,030 12/1953 Stacy 44-23 2,738,260 3/1956 Wolfson et a1. 4440 3,001,856 9/1961 Reerink et al. 44 23 3,036,900 5/ 1962 Honeycutt 44 25 3,236,611 2/1966 Behnke et a1. 4441 FOREIGN PATENTS 1,061,740 7/ 1959 Germany.

OTHER REFERENCES Formulations and Quality Control in Polyurethane Propellants, Harold E. Marsh, Jr., Ind. and Eng. Chem, vol. 52, #9, September 1960, pp. 768-771.

PATRICK P. GARVIN, Primary Examiner.

DANIEL W. WYMAN, Examiner.

C. F. DEES, Assistant Examiner. 

1. A SOLID FUEL COMPOSITION COMPRISING A MAJOR PORTION OF BITUMINOUS MATERIAL AND A MINOR PORTION OF A PARTICULATE MATERIAL SELECTED FROM THE GROUP CONSISTING OF PARTICULATE POLYSTYRENE AND PARTICULATE RIGID POLYURETHANE, SAID PARTICULATE MATERIAL MIXED WITH SAID BITUMINOUS MATERIAL AS DISPERSED PARTICLES IN A CONTINUOUS BITUMINUOUS PHASE.
 5. A SOLID FUEL COMPOSITION COMPRISING A MAJOR PORTION OF BITUMINOUS MATERIAL AND A MINOR PORTION OF NAPHTHALENE. 